Schedule 1 substances, in the sense of the Chemical Weapons Convention, are either

• toxic enough to be used as chemical weapons, or
• precursors of other listed substances.

As they have few, if any, legitimate uses, they may only be produced or used for research, medical, pharmaceutical or protective purposes, and then only in such quantities as are necessary for these purposes (never more than one tonne per year per country). Any production or use must be declared to the OPCW as per Part VI of the "Verification Annex".

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Guidelines for Schedule 1

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The following criteria shall be taken into account in considering whether a toxic chemical or precursor should be included in Schedule 1:

• It has been developed, produced, stockpiled or used as a chemical weapon as defined in Article II;
• It poses otherwise a high risk to the object and purpose of this Convention by virtue of its high potential for use in activities prohibited under this Convention because one or more of the following conditions are met:
  • It possesses a chemical structure closely related to that of other toxic chemicals listed in Schedule 1, and has, or can be expected to have, comparable properties;
  • It possesses such lethal or incapacitating toxicity as well as other properties that would enable it to be used as a chemical weapon;
  • It may be used as a precursor in the final single technological stage of production of a toxic chemical listed in Schedule 1, regardless of whether this stage takes place in facilities, in munitions or elsewhere;
• It has little or no use for purposes not prohibited under this Convention.

Toxic chemicals

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• O-Alkyl (10, incl. cycloalkyl) alkyl (Me, Et, n-Pr or i-Pr)-phosphonofluoridates, e.g.

Sarin: O-Isopropyl methylphosphonofluoridate

Soman: O-Pinacolyl methylphosphonofluoridate

• O-Alkyl (10, incl. cycloalkyl) N,N-dialkyl (Me, Et, n-Pr or i-Pr) phosphoramidocyanidates, e.g.

Tabun: O-Ethyl N,N-dimethylphosphoramidocyanidate

• O-Alkyl (H or 10, incl. cycloalkyl) S-2-dialkyl (Me, Et, n-Pr or i-Pr)-aminoethyl alkyl (Me, Et, n-Pr or i-Pr) phosphonothiolates and corresponding alkylated or protonated salts, e.g.

VX: O-Ethyl S-2-diisopropylaminoethyl methylphosphonothiolate

• Sulfur mustards:

2-Chloroethylchloromethylsulfide

Mustard gas: Bis(2-chloroethyl)sulfide

Bis(2-chloroethylthio)methane

Sesquimustard: 1,2-Bis(2-chloroethylthio)ethane

1,3-Bis(2-chloroethylthio)-n-propane

1,4-Bis(2-chloroethylthio)-n-butane

1,5-Bis(2-chloroethylthio)-n-pentane

Bis(2-chloroethylthiomethyl)ether

O-Mustard: Bis(2-chloroethylthioethyl)ether

• Lewisites:

Lewisite 1: 2-Chlorovinyldichloroarsine

Lewisite 2: Bis(2-chlorovinyl)chloroarsine

Lewisite 3: Tris(2-chlorovinyl)arsine

• Nitrogen mustards:

HN1: Bis(2-chloroethyl)ethylamine

HN2: Bis(2-chloroethyl)methylamine

HN3: Tris(2-chloroethyl)amine

• Saxitoxin

• Ricin

Precursors

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• Alkyl (Me, Et, n-Pr or i-Pr) phosphonyldifluorides, e.g.

DF: Methylphosphonyl difluoride

• O-Alkyl (H or 10, incl. cycloalkyl) O-2-dialkyl (Me, Et, n-Pr or i-Pr)-aminoethyl alkyl (Me, Et, n-Pr or i-Pr) phosphonites and corresponding alkylated or protonated salts, e.g.

QL: O-Ethyl O-2-diisopropylaminoethyl methylphosphonite

• Chlorosarin: O-Isopropyl methylphosphonochloridate

• Chlorosoman: O-Pinacolyl methylphosphonochloridate

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See also

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• Schedule 2
• Schedule 3

Chemical weapons | Military lists